<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>基础选择器t</title>
    <style>
        .blue {
            color: blue;
        }
        
        .star-string {
            color: red;
        }
    </style>
</head>

<body>
    <li class="blue">男生</li>
    <p>男生</p>
    <p class="star-string">男生</p>
    <div class="blue">女生</div>
    <div>女生</div>
</body>

</html>